1. Field of the Invention
The present invention relates to a display apparatus including a panel substrate having a display panel with x×y pixels arranged in a matrix at intersections of x (x is a natural number) signal lines disposed in a column direction and y (y is a natural number) gate lines disposed in a row direction.
2. Description of the Related Art
In active matrix display panels such as liquid crystal display panels, the number of pixels tends to increase with the increase in the degree of definition. With the increasing number of pixels, a so-called block sequential driving method has been used in which a panel driver for driving a display panel simultaneously applies drive voltages to pixel blocks each having a plurality of pixels continuously arranged in the scanning direction of the display panel.
In such a block sequential driving method, drive voltage signals to be transmitted to a plurality of pixels, for example, six, twelve, or twenty-four pixels included in each pixel block are transmitted to a display panel. Accordingly, there are several to several tens of signal lines between a signal generation circuit for generating the drive voltage signal and a panel driver.
However, if a high-resolution image such as a Full HD image (image size: 1920×1080), a 2K1K image (image size: 2048×1024), or a 4K2K image (image size: 4096×2048) is displayed on a display panel using the above-described block sequential driving method, it is required to operate a panel driver at a high speed so as to ensure sufficient time to transmit drive voltage signals to all pixels included in one frame in synchronization with a frame rate.
As a technique for rapidly transmitting drive voltage signals to all pixels included in one frame, Japanese Unexamined Patent Application Publication No. 2005-77745 discloses a driving apparatus for driving a display panel using a so-called pseudo line sequential driving method in which desired signal lines are sequentially selected one by one for sampling of a video signal from each of a plurality of signal line groups, which are obtained by dividing signal lines included in the display panel into the signal line groups, so that the sequential selection of the signal lines is simultaneously performed in the signal line groups. For example, if a single signal line group includes six signal lines and a Full HD image is displayed, drive voltage signals for 320 pixels are required to be simultaneously transmitted from a panel driver to pixels arranged on a display panel. In the above-described pseudo line sequential driving method, the number of signal lines between a signal generation circuit for generating the drive voltage signal and the panel driver can be increased to several hundreds of signal lines. As a result, it is possible to ensure sufficient time to transmit drive voltage signals to all pixels included in one frame.
A display apparatus in which a display panel is driven using the pseudo line sequential driving method includes, for example, a DSD (Digital Signal Driver) for performing pieces of signal processing such as gamma correction, color unevenness correction, and data sorting, a signal generation circuit for generating a drive voltage signal in accordance with pixel data output from the DSD and a pulse signal used to control the drive timing of a display panel, and the display panel that is driven in response to a signal generated by the signal generation circuit.
In such a display apparatus, drive voltage signals for 320 pixels are simultaneously transmitted to a display panel. Accordingly, for example, the DSD and the display panel are connected to each other at an FPC (Flexible Print Circuit) board, and the signal generation circuit is provided on the FPC board using a COP (Chip On FPC) method. The reason for this is that if a driver including the signal generation circuit is externally attached to the FPC board, a large number of drivers and several hundreds of output terminals of the DSD are required. This leads to upsizing of a display apparatus and an increase in system cost.